docs: def to_python(self, value):
          """
          `value` has slashs in it, that's why we inherit from `PathConverter`.
  
          E.g.: `commune/13200@latest/`, `departement/13@1860-07-01/` or
          `region/76@2016-01-01/Auvergne-Rhone-Alpes/`.
  
          Note that the slug is not significative but cannot be omitted.
          """
          if '/' not in value:
              return
  
          level, code = value.split('/')[:2]  # Ignore optional slug
  
          geoid = GeoZone.SEPARATOR.join([level, code])
          zone = GeoZone.objects.resolve(geoid)
  
          if not zone and GeoZone.SEPARATOR not in level:
              # Try implicit default prefix
              level = GeoZone.SEPARATOR.join([self.DEFAULT_PREFIX, level])
              geoid = GeoZone.SEPARATOR.join([level, code])
              zone = GeoZone.objects.resolve(geoid)
  
          return zone or NotFound()